There are 800,000 new strokes in the United States each year. Functional improvement of the upper paretic limb after stroke is mainly determined by improvement of the paretic hand, yet restoration of hand function after stroke often lags behind restoration of more proximal joints, and impairments are often resistant to therapeutic intervention. Systemic reviews of the literature report that using upper limb therapy robots results in gains in motor control, but there is little evidence of any effect on recovery of ADL ability. This may have been expected since relatively few clinical trials have been performed with robots that can address hand function. We have developed HEXORR, a hand robot that is unique in its ability to impart coordinated movement of 15 finger and thumb degrees-of-freedom within power and pinch grasp patterns. HEXORR also applies assistance patterns that automatically adapt to subject performance, with the goal of amplifying subject movements without taking over the task from the subject. This ensures active engagement on the part of the subject and completion of movement tasks to avoid frustration and passivity on the part of the subject. A clinical trial will be performed in subacute stroke subjects with impaired hand function Fourty-five subjects will be randomly assigned to 18 hours of training in HEXORR, 36 hours of training in HEXORR or 18 hours of conventional therapy. Clinical and biomechanical evaluations will be performed before and after the treatment period and at a 6-month followup. The results will determine the effectiveness of robotic hand therapy. This study will provide an opportunity for Biomedical Engineering undergraduates at Catholic University to participate in a NIH-funded clinical trial. Funds are requested to support two year-round undergraduate interns. They will be supervised by a graduate student and clinical staff. They will participate in all aspects of the study, including running of training sessions with stroke subjects, development of the testing protocols, analysis of data and dissemination of results. We believe this direct interaction with patients in the context of a structured research protocol is a key factor that wil motivate students to pursue doctoral level research careers in rehabilitation.